CAJ | 학술논문

分析曲轴箱增压和机械增压两种不同增压方式对二冲程发动机进排气过程中压力波动、进排气流速和流量变化过程等的影响，从而揭示不同增压方式下二冲程发动机进排气行为变化规律。研究表明，不同增压方式下，二冲程发动机进气过程存在非常明显的差别，而排气过程差异较小。使用机械增压替代曲轴箱增压，可增加压缩冲程缸内湍流强度，加速喷雾混合。在相同充气效率前提下，机械增压可提高扫气利用效率，增加内部EGR率，提升混合气温度，促进蒸发，同时增加混合气比热容，提高热效率。
분석곡축상증압화궤계증압량충불동증압방식대이충정발동궤진배기과정중압력파동、진배기류속화류량변화과정등적영향，종이게시불동증압방식하이충정발동궤진배기행위변화규률。연구표명，불동증압방식하，이충정발동궤진기과정존재비상명현적차별，이배기과정차이교소。사용궤계증압체대곡축상증압，가증가압축충정항내단류강도，가속분무혼합。재상동충기효솔전제하，궤계증압가제고소기이용효솔，증가내부EGR솔，제승혼합기온도，촉진증발，동시증가혼합기비열용，제고열효솔。
The influences of supercharging and crankcase charging on the pressure fluctuation ,flow velocity and mass flow rate of intake and exhaust gas were analyzed in order to find out the intake and exhaust behaviors under different charging sys-tems .The results show that the intake processes of two-stroke engine are significantly different ,but the exhaust processes are almost the same under different charging systems .The supercharging replacing crankcase charging can increase the in-cylinder turbulent flow and accelerate the mixing of fuel and air .At the same charge efficiency ,the supercharging can improve the scav-enging efficiency ,increase the internal EGR rate ,and improve the temperature of mixture and evaporation .In addition ,the su-percharging can increase the specific heat capacity of mixture and hence improve the thermal efficiency .